free_mutant/lib/inflector/methods.rb

# The Inflector transforms words from singular to plural, class names to table names, modularized class names to ones without,
# and class names to foreign keys. The default inflections for pluralization, singularization, and uncountable words are kept
# in inflections.rb.
#
# The Rails core team has stated patches for the inflections library will not be accepted
# in order to avoid breaking legacy applications which may be relying on errant inflections.
# If you discover an incorrect inflection and require it for your application, you'll need
# to correct it yourself (explained below).
module Inflector
  extend self

  # By default, +camelize+ converts strings to UpperCamelCase. If the argument to +camelize+
  # is set to <tt>:lower</tt> then +camelize+ produces lowerCamelCase.
  #
  # +camelize+ will also convert '/' to '::' which is useful for converting paths to namespaces.
  #
  # Examples:
  #   "active_record".camelize                # => "ActiveRecord"
  #   "active_record".camelize(:lower)        # => "activeRecord"
  #   "active_record/errors".camelize         # => "ActiveRecord::Errors"
  #   "active_record/errors".camelize(:lower) # => "activeRecord::Errors"
  #
  # As a rule of thumb you can think of +camelize+ as the inverse of +underscore+,
  # though there are cases where that does not hold:
  #
  #   "SSLError".underscore.camelize # => "SslError"
  def camelize(lower_case_and_underscored_word, first_letter_in_uppercase = true)
    if first_letter_in_uppercase
      lower_case_and_underscored_word.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
    else
      lower_case_and_underscored_word.to_s[0].chr.downcase + camelize(lower_case_and_underscored_word)[1..-1]
    end
  end

  # Makes an underscored, lowercase form from the expression in the string.
  #
  # Changes '::' to '/' to convert namespaces to paths.
  #
  # Examples:
  #   "ActiveRecord".underscore         # => "active_record"
  #   "ActiveRecord::Errors".underscore # => active_record/errors
  #
  # As a rule of thumb you can think of +underscore+ as the inverse of +camelize+,
  # though there are cases where that does not hold:
  #
  #   "SSLError".underscore.camelize # => "SslError"
  def underscore(camel_cased_word)
    word = camel_cased_word.to_s.dup
    word.gsub!(/::/, '/')
    word.gsub!(/([A-Z]+)([A-Z][a-z])/,'\1_\2')
    word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
    word.tr!("-", "_")
    word.downcase!
    word
  end

  # Replaces underscores with dashes in the string.
  #
  # Example:
  #   "puni_puni" # => "puni-puni"
  def dasherize(underscored_word)
    underscored_word.gsub(/_/, '-')
  end

  # Removes the module part from the expression in the string.
  #
  # Examples:
  #   "ActiveRecord::CoreExtensions::String::Inflections".demodulize # => "Inflections"
  #   "Inflections".demodulize                                       # => "Inflections"
  def demodulize(class_name_in_module)
    class_name_in_module.to_s.gsub(/^.*::/, '')
  end

  # Creates a foreign key name from a class name.
  # +separate_class_name_and_id_with_underscore+ sets whether
  # the method should put '_' between the name and 'id'.
  #
  # Examples:
  #   "Message".foreign_key        # => "message_id"
  #   "Message".foreign_key(false) # => "messageid"
  #   "Admin::Post".foreign_key    # => "post_id"
  def foreign_key(class_name, separate_class_name_and_id_with_underscore = true)
    underscore(demodulize(class_name)) + (separate_class_name_and_id_with_underscore ? "_id" : "id")
  end

  # Ruby 1.9 introduces an inherit argument for Module#const_get and
  # #const_defined? and changes their default behavior.
  if Module.method(:const_get).arity == 1
    # Tries to find a constant with the name specified in the argument string:
    #
    #   "Module".constantize     # => Module
    #   "Test::Unit".constantize # => Test::Unit
    #
    # The name is assumed to be the one of a top-level constant, no matter whether
    # it starts with "::" or not. No lexical context is taken into account:
    #
    #   C = 'outside'
    #   module M
    #     C = 'inside'
    #     C               # => 'inside'
    #     "C".constantize # => 'outside', same as ::C
    #   end
    #
    # NameError is raised when the name is not in CamelCase or the constant is
    # unknown.
    def constantize(camel_cased_word)
      names = camel_cased_word.split('::')
      names.shift if names.empty? || names.first.empty?

      constant = Object
      names.each do |name|
        constant = constant.const_defined?(name) ? constant.const_get(name) : constant.const_missing(name)
      end
      constant
    end
  else
    def constantize(camel_cased_word) #:nodoc:
      names = camel_cased_word.split('::')
      names.shift if names.empty? || names.first.empty?

      constant = Object
      names.each do |name|
        constant = constant.const_defined?(name, false) ? constant.const_get(name) : constant.const_missing(name)
      end
      constant
    end
  end

  # Turns a number into an ordinal string used to denote the position in an
  # ordered sequence such as 1st, 2nd, 3rd, 4th.
  #
  # Examples:
  #   ordinalize(1)     # => "1st"
  #   ordinalize(2)     # => "2nd"
  #   ordinalize(1002)  # => "1002nd"
  #   ordinalize(1003)  # => "1003rd"
  def ordinalize(number)
    if (11..13).include?(number.to_i % 100)
      "#{number}th"
    else
      case number.to_i % 10
        when 1; "#{number}st"
        when 2; "#{number}nd"
        when 3; "#{number}rd"
        else    "#{number}th"
      end
    end
  end
end